The area of Mississippi Territory was increased in 1804 and again in 1812. On December 10, 1817, Mississippi was admitted into the Union as a state and Alabama Territory to the east was spun off. List of delegates representing the district On April 7, 1798, the Mississippi Territory was created. A non-voting delegate was elected at-large beginning March 4, 1801. References Territory Mississippi Territory Mississippi Territory Constituencies established in 1801 1801 establishments in Mississippi Territory 1817 disestablishments in Mississippi Territory Constituencies disestablished in 1817